Expanded Polytetrafluoroethylene Sheet Research Articles

Mechanical support for bridge to transplant in an infant with post-cardiotomy end-stage heart failure and complete heart block: report of a case.

The patient was diagnosed with perimembranous ventricular septal defect (VSD). She underwent VSD closure and muscle bundle resection across right ventricular outflow tract at the age of 3 months. Since then, she had suffered from severe heart failure and complete heart block. Permanent pacemaker generator was implanted in the left hypochondrium. She was depended on continuous catecholamine administration, so transferred to our hospital for further management. On arrival, her body weight was 5686g (- 2.7 SD). She underwent Excor pediatric left ventricular assist device implantation at the age of 9 months. Because the position of the left ventricular assist device cannula interfered with the pacemaker, herein, the pacemaker pocket was newly created in the left thoracic cavity. An 1mm in thickness of expanded polytetrafluoroethylene sheet was trimmed and sutured under the anterolateral wall of left thoracic cavity as a pacemaker pocket. Bipolar ventricular lead was sutured on left ventricular apex and basal wall to face each other, mimicking cardiac regeneration therapy. Even though she unfortunately required right diaphragmatic plication for iatrogenic phrenic nerve palsy, her respiratory function was well maintained; therefore, secondary right heart failure was not observed. Her cardiopulmonary function was quite stable until post-operative day 275 when the patient was transferred to another hospital for heart transplantation.

Successful pericardial repair and coverage for late pacemaker lead-related atrial perforation and pneumothorax: a case report

BackgroundVarious complications of permanent pacemaker implantation have been reported. However, late pacemaker lead-related myocardial perforation rarely occurs. Conservative treatment is generally selected, if possible, but open heart surgery or catheter lead removal should be considered in symptomatic patients. We herein describe a patient who was successfully treated by pericardial repair and coverage for late pacemaker lead-related atrial perforation and pneumothorax.Case presentationA woman in her 80s who had undergone permanent pacemaker implantation 2 years previously visited our hospital because of dyspnea. She had also been treated for right pneumothorax 1 year previously. A chest radiograph and computed tomography scan showed right pneumothorax and pericardial emphysema with no effusion. Because similar findings had been obtained at the previous onset of pneumothorax, we suspected delayed myocardial perforation and lung injury due to the screw-in lead in the right atrium. No myocardial bleeding, cardiac tamponade, or pacing failure was present. The cardiovascular surgeon judged that open-heart lead extraction would be difficult because of the patient’s poor performance status; therefore, thoracoscopic pericardial repair with an expanded polytetrafluoroethylene sheet and coverage with anterior mediastinal adipose tissue was attempted to prevent recurrent pneumothorax. The patient was successfully treated without lead extraction or open heart surgery. At 1.5 years postoperatively, she had developed no recurrence of pneumothorax or pacing failure.ConclusionsPericardial repair and coverage can be an effective strategy for pacemaker lead-related pneumothorax without pacing failure or bleeding.

Clinical impact of spacer placement surgery with expanded polytetrafluoroethylene sheet for particle therapy

BackgroundSpacer placement surgery is useful in particle therapy (PT) for patients with abdominopelvic malignant tumors located adjacent to the gastrointestinal tract. This study aimed to assess the safety, efficacy, and long-term outcomes of spacer placement surgery using an expanded polytetrafluoroethylene (ePTFE) spacer.MethodsThis study included 131 patients who underwent ePTFE spacer placement surgery and subsequent PT between September 2006 and June 2019. The overall survival (OS) and local control (LC) rates were calculated using Kaplan-Meier method. Spacer-related complications were classified according to the National Cancer Institute Common Terminology Criteria for Adverse Events (version 5.0).ResultsThe median follow-up period after spacer placement surgery was 36.8 months. The 3-year estimated OS and LC rates were 60.5% and 76.5%, respectively. A total of 130 patients (99.2%) were able to complete PT. Spacer-related complications of ≥ grade 3 were observed in four patients (3.1%) in the acute phase and 13 patients (9.9%) in the late phase. Ten patients (7.6%) required removal of the ePTFE spacer.ConclusionsSpacer placement surgery using an ePTFE spacer for abdominopelvic malignant tumors is technically feasible and acceptable for subsequent PT. However, severe spacer-related late complications were observed in some patients. Since long-term placement of a non-absorbable ePTFE spacer is associated with risks for morbidity and infection, careful long-term follow-up and prompt therapeutic intervention are essential when complications associated with the ePTFE spacer occur.Trial registrationretrospectively registered.

Application of Biosheets as Right Ventricular Outflow Tract Repair Materials in a Rat Model

PurposesWe report the experimental use of completely autologous biomaterials (Biosheets) made by “in-body tissue architecture” that could resolve problems in artificial materials and autologous pericardium. Here, Biosheets were implanted into full-thickness right ventricular outflow tract defects in a rat model. Their feasibility as a reparative material for cardiac defects was evaluated.MethodsAs the evaluation of mechanical properties of the biosheets, the elastic moduli of the biosheets and RVOT-free walls of rats were examined using a tensile tester. Biosheets and expanded polytetrafluoroethylene sheet were used to repair transmural defects surgically created in the right ventricular outflow tracts of adult rat hearts (n = 9, each patch group). At 4 and 12 weeks after the operation, the hearts were resected and histologically examined.ResultsThe strength and elastic moduli of the biosheets were 421.3 ± 140.7 g and 2919 ± 728.9 kPa, respectively, which were significantly higher than those of the native RVOT-free walls (93.5 ± 26.2 g and 778.6 ± 137.7 kPa, respectively; P < 0.005 and P < 0.001, respectively). All patches were successfully implanted into the right ventricular outflow tract-free wall of rats. Dense fibrous adhesions to the sternum on the epicardial surface were also observed in 7 of 9 rats with ePTFE grafts, whereas 2 of 9 rats with biosheets. Histologically, the vascular-constructing cells were infiltrated into Biosheets. The luminal surfaces were completely endothelialized in all groups at each time point. There was also no accumulation of inflammatory cells.ConclusionsBiosheets can be formed easily and have sufficient strength and good biocompatibility as a patch for right ventricular outflow tract repair in rats. Therefore, Biosheet may be a suitable material for reconstructive surgery of the right ventricular outflow tract.

Twenty years' use of expanded polytetrafluoroethylene sheet for an artificial cardiac pacemaker.

Physicians can prolongedly use expanded polytetrafluoroethylene sheets for fixation of artificial cardiac pacemakers to avoid pacemaker lead displacement. The sheets can also be used to prevent implant rejection in patients with metal allergies.

A case of cardiac strangulation following epicardial pacemaker implantation

An 8-year-old boy had undergone permanent epicardial pacemaker implantation with a Y-shaped bipolar ventricular lead on day 6 after birth for treatment of congenital complete atrioventricular block. He was found to have pulmonary stenosis and mitral stenosis by follow-up echocardiography. Further studies including computed tomography and cardiac catheterization revealed that the pacemaker lead had completely encircled the cardiac silhouette and was in a state of “cardiac strangulation”. We removed the previous pacing leads and generator and implanted a new epicardial dual-chamber pacing system in the right atrium and right ventricle. Additionally, an expanded polytetrafluoroethylene sheet was placed between the new leads and the heart to prevent recurrence of cardiac strangulation.

Surgical spacer placement using an expanded polytetrafluoroethylene sheet in proton beam therapy for pediatric solid tumors

Surgical spacer placement using an expanded polytetrafluoroethylene sheet in proton beam therapy for pediatric solid tumors

Recurrent sternal thymoma after thymectomy by video-assisted thoracic surgery

An 81-year-old man underwent thymectomy by video-assisted thoracic surgery for a mediastinal tumor. The pathological diagnosis was Masaoka stage II type B3 thymoma. Thirty-six months later, he presented with a growing mass on his anterior chest wall. Computed tomography showed a lobulated tumor in the sternum with bone destruction. Positron-emission tomography-computed tomography showed a maximal standardized uptake of 12.3 in the tumor. Core needle biopsy confirmed a metastatic sternal tumor from a type B3 thymoma. We partially resected the sternum and reconstructed the defect using an expanded polytetrafluoroethylene sheet. The patient has remained recurrence-free for 3 years after the second surgery.

In situ tissue regeneration using a warp-knitted fabric in the canine aorta and inferior vena cava.

Materials used in paediatric cardiac surgery have drawbacks of deterioration, calcification and pseudointimal proliferation resulting in haemodynamic disturbance. The aim of this study was to investigate whether these drawbacks can be overcome by in situ tissue regeneration using a newly developed synthetic hybrid fabric (SHF). The SHF is an expandable, warp-knitted fabric composed of a combination of biodegradable [poly-l-lactic acid (PLLA)] and non-biodegradable (polyethylene terephthalate) yarns. The fabric is coated with cross-linked gelatin. Mechanical properties of the SHF were compared with those of 2 commercial products: expanded polytetrafluoroethylene sheet and glutaraldehyde-treated bovine pericardium. An oval-shaped defect created in the canine descending aorta or inferior vena cava was filled with the SHF patch. After 2 weeks and 1, 3, 6 and 12 (or 24 in the inferior vena cava) months, the patch was removed for histological examination and evaluation of the remaining PLLA. The SHF exhibited satisfactory tensile and suture retention strength for surgical implantation similar to or better than the 2 commercial products. Tissue regeneration was induced with multilayered smooth muscle cells and collagen fibres on both sides of the patch, along with a mature endothelial layer and tissue connections containing vasa vasorum across the patch in the aorta and inferior vena cava. Inflammatory reactions were minimal, and no calcium deposition occurred. The molecular weight of PLLA was reduced to half at 12 months after implantation. The SHF may solve the drawbacks of the existing products. Further studies of the expandability of the SHF patch after degradation of PLLA are warranted.

Frontalis suspension with an expanded polytetrafluoroethylene sheet for congenital ptosis repair

Congenital ptosis with poor levator function is most often repaired with a frontalis suspension procedure. Autogenous fascia lata grafting is generally effective, with low rates of infection and granuloma formation. However, contraction of the grafted fascia lata may cause eyelash inversion, tarsal deformity, and/or lagophthalmos. Conversely, several synthetic suspensory materials have been used for frontalis suspension, among which polytetrafluoroethylene has been reported to be comparable to the fascia lata. However, in some studies using polytetrafluoroethylene strips or sutures, complications such as infection and granuloma formation were a significant problem. This study evaluated the outcomes of frontalis suspension with an expanded polytetrafluoroethylene sheet for congenital ptosis repair in 97 patients (130 eyelids). No ptosis recurrence was reported in an average follow-up of 31.6 months (range: 6-102 months). Six of the 130 eyelids (4.6%) had complications. Based on these results, frontalis suspension with an expanded polytetrafluoroethylene sheet for congenital ptosis repair can be considered safe and effective and be recommended for clinical use.

Treatment for infection of artificial dura mater using free fascia lata.

Synthetic artificial dura mater materials, such as expanded polytetrafluoroethylene sheets, are widely used in dura mater reconstruction in cases involving brain tumors or trauma surgery. In patients with postoperative infection related to the use of artificial dura mater, surgical debridement of the infected wound and removal of the artificial dura mater materials are necessary to control infection. In cases involving cerebrospinal fluid leakage, dura mater reconstruction must be performed immediately. Many useful techniques for performing dura mater reconstruction to treat postoperative infection have been reported; however, some have drawbacks with respect to the need for microvascular anastomosis or difficulties in obtaining watertight closure. We successfully treated 6 patients with postoperative artificial dura mater infection using free thigh fascia lata. Some surgeons believe that the use of free fascia in infected wounds is dangerous because free fascia is a non-vascularized tissue. However, performing complete debridement and covering such free fascia with well-vascularized tissue allow the fascia to become vascularized and tolerant of infection. Therefore, if the blood flow in the scalp is acceptable after a sufficient debridement, free fascia lata can be used for reconstruction in patients with postoperative infection of artificial dura mater. Furthermore, skull reconstruction can be performed safely and easily with solid-type artificial bone, sometimes combined with tissue expansion, thus resulting in good aesthetic outcomes.

Cranial Reconstruction following the Removal of an Infected Synthetic Dura Mater Substitute.

Background:The objective of this study was to describe the outcomes of an algorithmic approach to cranial reconstruction following the removal of an infected synthetic dura mater substitute due to postcraniotomy infection.Methods:A retrospective review was conducted of the cases of 12 patients who underwent cranial reconstruction from 2006 to 2013 after the removal of an infected expanded polytetrafluoroethylene sheet (a synthetic dura mater substitute) due to postcraniotomy infection.Results:Average patient age was 46 years (range, 19–70 years). Follow-up was 4.6 years. The expanded polytetrafluoroethylene sheets were implanted after decompressive craniectomy or after combined resection of the dura mater and a tumor. Epidural, but not subdural, abscesses were found in 6 patients, in whom a sufficient capsule developed underneath the synthetic dura mater. Both epidural and subdural abscesses were found in the remaining 6 patients, and the capsule remained intact after debridement of the subdural abscesses in half of them. Secondary cranial reconstruction was safely performed by leaving the capsule intact in the 9 cases in which no additional dural reconstruction was performed. In the remaining 3 patients, in whom no capsule remained after debridement, secondary cranial reconstruction was carried out by leaving the pericranium over the brain surface. None of the patients developed postoperative complications in follow-up periods.Conclusions:Staged cranial reconstruction after the removal of an infected synthetic dura mater substitute using an algorithmic approach is feasible and safe, produces satisfactory cosmetic results, and is not associated with any complications.

Treatment of Contact Dermatitis Associated With Spinal Cord Stimulator Pulse Generator—Technical Note

Expanded polytetrafluoroethylene sheets have been successfully used as a biologic barrier in the treatment of pacemaker contact dermatitis. In this report, we describe two patients with contact dermatitis related to the implantable pulse generator of a spinal cord stimulator who were treated with expanded polytetrafluoroethylene as a barrier. Resolution of the dermatitis was achieved in both cases. This technique is an effective way of treating contact dermatitis related to implantable pulse generators, without the need for explantation of the neuromodulation system.

Reconstruction of the right ventricular outflow tract after surgical removal of a cardiac hemangioma

An asymptomatic 73-year-old man underwent resection of a cardiac tumor arising from the right ventricular outflow tract, and reconstruction of the right ventricular outflow tract using an expanded polytetrafluoroethylene sheet. Histological examination revealed a cavernous-capillary type cardiac hemangioma, which is a very rare cardiac tumor.

Long-term results of a cardiovascular implantable electronic device wrapped with an expanded polytetrafluoroethylene sheet

The use of an expanded polytetrafluoroethylene (ePTFE) sheet wrapping device for patients with pacemaker contact dermatitis is still controversial. This study aimed to retrospectively investigate the occurrence rate of allergies and other complications after implantation of a cardiovascular implantable electronic device (CIED) wrapped with an ePTFE sheet. A total of 4,497 procedures of CIED implantation were performed at our institution between January 1993 and April 2010. Among 19 patients who underwent implantation of an electronic cardiac device wrapped with an ePTFE sheet, device implantation was performed in 11 patients for secondary prevention of device contact sensitivity, in 7 patients for primary prevention of device contact sensitivity, and in 1 patient for avoiding over-sensing of myopotentials. During follow-up periods (mean 46±34months), there were no allergic or inflammatory reactions to components of the device or ePTFE itself. Among 11 patients with a device wrapped with an ePTFE sheet for secondary prevention, 5 patients completed device replacement due to battery depletion and 3 patients had infections from the device. Wrapping implantable devices with an ePTFE sheet is an effective way of preventing device sensitivity in patients who require CIED therapy. However, the risk of infection from the device should be taken into consideration.

Microroll retractor for surgical resection of brainstem cavernoma

Background Safe and complete surgical resection of brainstem cavernoma is difficult without injury surrounding normal structures because the lesions are deep and intra-axial. In this article, the authors describe the “microroll retractor” technique for brainstem cavernoma surgery. Methods The microroll retractor is made of expanded polytetrafluoroethylene sheet. The sheet is cut in several sizes of square piece and transformed into a tubular shape. We insert this roll retractor via minimal brain incision and keep surgical corridor without usual spatulas during lesionectomy. Results This technique was adopted for 7 patients with brainstem cavernomas. In all patients, we achieved total excision; improvement was recorded in 6 patients, and no change was recorded in 1 patient. Conclusions The microroll retractor is extremely simple but provides enough surgical corridors for safe total resection of brainstem cavernomas.

Surgical Treatment of Spinal Lipoma Without Spina Bifida at Lumbar Region -Three Case Reports-

Three men aged 40 to 60 years presented with rare lumbar spinal intradural lipomas without spina bifida manifesting as worsening numbness, pain of the lower extremities, and bladder dysfunction. All 3 patients underwent decompressive laminectomy. The lipoma and cauda equina nerves were dissected from the dura mater under the operating microscope, untethering the spinal cord and returning the cauda equina nerves to the original position. Duralplasty was performed using an expanded polytetrafluoroethylene sheet. Postoperatively, all patients experienced improvement of their neurological deficits. In the surgical treatment of spinal lipomas, the primary purpose is untethering and decompression, which can be achieved by untethering the spinal cord, returning the cauda equina nerves to the normal position, laminectomy, and duralplasty, without removal of the lipoma.

Treatment for Postoperative Intracranial Infection after Duraplasty with Expanded Polytetrafluoroethylene Sheet

Treatment for Postoperative Intracranial Infection after Duraplasty with Expanded Polytetrafluoroethylene Sheet

Expanded polytetrafluoroethylene valved conduit and patch with bulging sinuses in right ventricular outflow tract reconstruction

No specific prosthetic material is currently recognized as being the most suitable for right ventricular outflow tract reconstruction for congenital heart defects. Prosthetic valves are subject to wear and stress because they do not create vortex flow, which helps natural valves to close. We designed a fan-shaped expanded polytetrafluoroethylene valved conduit and patch with bulging sinuses that create vortex flow, making them more reliable over the long term. Bulging sinuses were formed on a sheet of expanded polytetrafluoroethylene using a specially designed mold. Fan-shaped expanded polytetrafluoroethylene sheets (0.1 mm thick) were anastomosed to the edge of the bulging sinuses as valve leaflets, creating monocuspid, bicuspid, or tricuspid valves. These valves were implanted in 157 patients undergoing right ventricular outflow tract reconstruction (age 16 days to 45.4 years, median 2.0 years), in 48 patients as a conduit, and in 109 patients as a patch. Valve function was followed up by echocardiography for 5.6 to 63.7 months (mean 20.8 months). There was no mortality or morbidity, and no patients required reoperation during follow-up. No patients had stenosis, and regurgitation was less than mild in all patients with conduits and moderate in 15 patients (13.8%) with patches, but moderate regurgitation did not further develop during follow-up. Valve motion was fully maintained in all patients. The expanded polytetrafluoroethylene valved conduits and patches with bulging sinuses showed excellent early-to-midterm results. The valved conduits and patches seem to be promising alternatives to homografts in right ventricular outflow tract reconstruction. Their function will be followed up further.

Two Pretreatment of Expanded Polytetrafluoroethylene Sheet for the Cross-section Determination of Grafted Structures by SEM and FTIR Microscopy

Two Pretreatment of Expanded Polytetrafluoroethylene Sheet for the Cross-section Determination of Grafted Structures by SEM and FTIR Microscopy